1. Field of the Invention
This invention relates to an ingrown nail correcting device for correcting an ingrown nail by being fitted to a toe or a finger, or particularly to a big toe or a thumb having an ingrown nail.
2. Description of the Prior Art
Ingrown nail correcting devices of various shapes and structures have been developed so far. Such conventional ingrown nail correcting devices include, for example, an ingrown nail correcting device comprising an elastic correcting member having rubber elasticity or a resilient metal plate which is provided with hook-shaped engaging members on both longitudinal side-ends thereof to hook both side-ends of the ingrown nail, as described in the Patent Document 1, an ingrown nail correcting device made of a shape-memory alloy or a shape-memory resin which is bonded onto a dorsum of the nail and heated to bend the ingrown nail in the correcting direction, as described in the Patent Document 2, and an ingrown nail correcting device, comprising a long and narrow resilient thin plate having an engaging member part formed by folding back a front end downward so as to hook the front end part of the ingrown nail, which is fixed to the upper face of the nail by adhesive tape to maintain the state that the engaging member part is engaged with the front end part of the ingrown nail, as described in the Patent Document 3.
Such conventional ingrown nail correcting devices include:    [Patent Document 1] Patent Publication No. 2003-265508,    [Patent Document 2] Patent Publication No. H8-215227, and    [Patent Document 3] Utility Model Registration No. 3091516.
However, in the ingrown nail correcting device having the structure as described in the Patent Document 1, the elastic correcting member having the rubber elasticity is structured so that it may apply the elastic contraction force in the direction of the width of the nail. Therefore, the elastic contraction force largely acts on the engaging members on both sides of the elastic correcting member engaged with both side-ends of the ingrown nail, as the action force works in the direction of narrowing the width between the two side-ends of the ingrown nail, while the action force working in the direction of pulling the ingrown nail up, or in other words in the direction of correcting the ingrown nail is small. Therefore, the force does not work effectively to correct the ingrown nail, which represents a problem.
According to the ingrown nail correcting device made of the shape-memory alloy or the shape-memory resin as described in the Patent Document 2, when the adhesive force of the adhesive agent for bonding the correcting device to the dorsum of the nail is weak, the correcting device is easily removed from the dorsum of the nail and the correction cannot be performed. On the other hand, when the adhesive force is strong, removal of the correcting device from the nail becomes difficult, which is also a problem. In addition, since the correcting device needs to be heated by a dryer or warm water to correct the ingrown nail, it is difficult to exert the corrective force continuously for a long time, and the correction cannot be performed as well when heating is stopped as the correcting device returns into the original shape, which also represents a problem.
According to the ingrown nail correcting device as described in the Patent Document 3, the correcting device comprises the long and narrow resilient thin plate having the engaging member part formed by folding back the front end downward so as to hook the front end part of the ingrown nail. Therefore, there is an advantage that the engaging member part can easily hook the front end part of a side-end edge or a side-end edge on the other side of the ingrown nail and can be easily fitted to the ingrown nail when using the correcting device. However, even when the correcting device is fixed onto the upper face of the nail by the adhesive tape in the state that the engaging member part may hook the front end part of the ingrown nail, the engaging member part hardly has a sufficient corrective force for pulling the ingrown nail up. In addition, even when the correcting part of the device is resiliently deformed toward the upper face of the ingrown nail positively with the front end of the ingrown nail serving as a fulcrum so that the engaging member part may have the corrective force for pulling the ingrown nail up by the resilience, the corrective force is applied in the direction of moving the engaging member part forward from and off the front end of the ingrown nail but is hardly applied in the direction for correcting the ingrown nail since the fulcrum exists at the front end of the ingrown nail. Thus, an effective corrective force cannot be obtained, which represents a problem.